Desplatsia mildbraedii Burret

Wellsow, Julia, Hart, Michelle, Wilkie, Peter & Harris, David J., 2019, A taxonomic revision of the African genus Desplatsia Bocq. (Malvaceae - Grewioideae), European Journal of Taxonomy 584 (584), pp. 1-38 : 24-25

Desplatsia mildbraedii Burret

Figs 1D , 2F , 3D , 4E , 8 , Table 1

Wissenschaftliche Ergebnisse der Deutschen Zentral-Afrika-Expedition, 1907–1908, unter Führung Adolf Friedrichs, Herzogs zu Mecklenburg. Vol. 2: Botanik: 497 ( Mildbraed 1912). – Type: DEMOCRATIC REPUBLIC OF CONGO • Irumu, Kifuku; G. W. J. Mildbraed 2882; syntype: B, presumed † • Turuma, Poyo; 2°42′ N, 30°21′ E; Apr. 1908; G. W. J. Mildbraed 2836; syntype: B, presumed †, lectotype: BM, designated here, isolectotype: BR [ BR0000013205478 ] .

Other material studied

CAMEROON •village of Mayouka,near Muguka; Jul.1917; F.Fleury33163; BR [ BR0000020059491 ], P • 15 km E of Dimako ; 4°23′ N, 13°34′ E; 15 Dec.1965; A. J. M.Leeuwenberg 7348; BR [ BR0000019964225 ], K, P, WAG [ WAG.1845698] 3 sheets • Melen II Map Abong-mbang; 3°34′ N, 13°02′ E; 20 Apr. 1961; R. Letouzey 3877; BR [ BR0000020438371 ], K, P, WAG [ WAG.1845673] • near Ngola, 30 km E of Yokadouma ; 3°29′ N, 15°19′ E; 10 May 1963; R. Letouzey 4979; BR [ BR0000019964201 ], K, P, WAG [ WAG.1845672] • 16 km W of Yenga, village of Port Gentil ; 2°03′ N, 15°10′ E; 20 Apr. 1971; R. Letouzey 10697; BR [ BR0000020059514 ], K, P .

CENTRAL AFRICAN REPUBLIC • Moussaboula Village , 7 km N of Bayanga; 3°55′ N, 15°23′ E; 1 May 1985; R. W. Carroll 25; BR [ BR0000020061104 ] • R. W. Carroll 1072; MO • R. W. Carroll 1084; MO • R. W. Carroll 1092; MO • Kongana camp; 2°47′ N, 16°25′ E; 16 Dec. 1993; D. J. Harris 4005; E [ E00930972 ] • Kongana research camp; 2°47′ N, 16°16′ E; 1 Feb. 1994; D. J. Harris 4397; E [ E00930950 ] • Sangha-Mbaere, Kongana camp; 2°47′ N, 16°26′ E; 30 Jan. 1996; D. J. Harris 5408; E [ E00930974 ] • Eleme ya Ngombe plot, W of Sangha River ; 2°58′ N, 16°11′ E; 3 Dec. 2000; D. J. Harris 7303; E [ E00930971 ] • W of Sangha River , 12 km NE of Bayanga; 3°01′ N, 16°11′ E; 13 May 2001; D. J. Harris 7709; E [ E00930973 ] • 30 Dec. 1948; Tisserant ( Équipe ) 1303; BM, BR [ BR0000020059538 ], P • Boukoko; 3°54′ N, 17°55′ E; 11 Jan. 1949; Tisserant ( Équipe ) 1324; BM, BR [ BR0000020059521 ], P • Bayanga on the road to Dzanga; 2°54′ N, 16°15′ E; 20 Feb. 1976; Wraber LJU 49486; K .

DEMOCRATIC REPUBLIC OF CONGO • Bambesa ; 3°26′ N, 25°41′ E; 27 Mar. 1953; P. Gérard 566 B; BR [ BR0000020059552 ] • ibid.; 26 Feb. 1957; P. Gérard 2669; BR [ BR0000020059545 ] 2 sheets • Epulu , “Zone de Mambesa (Ituri)” [area of Mambesa (Ituri)]; 1°25′ N, 28°35′ E; 12 Mar. 1986; T. Hart 540; BR [ BR0000019965543 ] • Nala ; 2°52′ N, 27°39′ E; 1907; F. Seret 789; BR [ BR0000020059644 ] 4 sheets .

UGANDA • 4 miles E of Mukono ; 0°21′ N, 32°48′ E; 20 Dec. 1951; H. C. Dawkins 685; K • Budongo Forest ; 1°38′ N, 31°35′ E; W. J. Eggeling 1464; K • Budongo Forest , Bunyoro; 1°38′ N, 31°35′ E; 15 Jul. 1935; W. J. Eggeling 1745; BR [ BR0000020059507 ] • ibid.; Jul. 1935; W. J. Eggeling 2131; K .

Description

HABIT. Tree to 9–25 m tall, DBH to (15–) 40–80 cm, branches and twigs slightly tomentose and with scattered simple hairs.

LEAVES. With 3–4-fid stipules, finely divided almost to the base, 5–10 mm long, 2 mm wide, lanceolate to filamentous, slightly rusty-tomentose and with scattered long hairs; petiole 1.2–1.8 cm long with similar indumentum; leaf blade usually drying greenish-brown, oblong, sub-leathery, 10–21 cm long, 2.8–8 cm wide, apex acute to slightly acuminate, base rounded to slightly asymmetrically subcordate, regularly toothed margin, slightly puberulous or almost glabrous above, densely, evenly-spaced stellate hairs below, with distinctly longer hairs on midrib and secondary veins, secondary veins rarely looping; domatia absent.

INFLORESCENCE. An axillary or terminal cyme of 4–8 pedicellate flowers, loose; peduncle 1–2.5(–4) cm long covered by the same indumentum as the stipules; involucral bracts 6–8, 3 inner ovate-elliptic, 3 mm long, 2 mm wide, and 3–5 outer oblong-lanceolate, not enveloping in the buds and falling off early.

FLOWERS. Pedicellate, pedicels 0.8–2 cm long with similar indumentum as the stipules; buds elliptic and brown-velvety. Sepals cream to pale yellow, fleshy but brittle, 1–1.5 cm long, 2–4 mm wide, not fringed at tip, tomentose and with some longer hairs outside. Petals lanceolate to obovate-oblong, 4–4.8 mm long, 1–2.4(–3) mm wide. Ovary 5–7-locular.

FRUITS. Globose to subglobose, 6.5–9.5 cm long, 5–8.5 cm wide, obscurely grooved, glabrous.

SEEDS. Obovoid, 0.7–1.7 cm long, 0.3–1 cm wide.

Distribution (see Fig. 8 )

Cameroon, Central African Republic, Democratic Republic of Congo, Uganda.

Habitat

Terra firma forest, both old growth and selectively logged semi-evergreen forest. At altitudes of 350– 1200 m a.s.l.

Phenology

Flower: December–May, fruit: December, February, July.

Proposed IUCN status

Least Concern (LC). Desplatsia mildbraedii has an EOO of 441 153 km 2 and a wide distribution range across the north of the Congo basin. This species has a relatively small AOO of 80 km 2, but since there are no major threats and the species has fairly recently been collected in protected areas of the Dzanga- Sangha Reserve ( Harris 2002; Harris & Wortley 2008) and the Okapi Wildlife Reserve ( Democratic Republic of Congo), thus ensuring some level of protection, D. mildbraedii is classed as Least Concern.

Notes

First-step lectotypification for D. mildbraedii was done by Wilczek (1963). Syntypes are available at BM and BR; here, we select the BM specimen as lectotype, as it bears flowers and fruits which we have examined in London.

Desplatsia mildbraedii is clearly recognized as a separate species by us despite doubts on the validity of earlier separations of D. mildbraedii from D. dewevrei ( Verdcourt 2001) . The key characters found during this revision that reliably set D. mildbraedii apart from D. dewevrei are shown in Table 1.

Figures

Fig. 1. Illustration of Desplatsia Bocq. leaves. A. D. subericarpa Bocq. (Harris 1387 (E)). B. D. chrysochlamys (Mildbr. & Burret) Mildbr. & Burret (Harris 5402 (E)). C. D. dewevrei (De Wild. & T.Durand) Burret (Harris 7025 (E)). D. D. mildbraedii Burret (Harris 4397 (E)). Scale bars = 2 cm. Boxed enlargements of petiole (in B–D) and midrib (A–D) are magnified 10× to represent the view through a typical 10× hand lens. Boxed enlargements of petiole (A) and stipules (A–D) are magnified 6×. Images are taken from Harris & Wortley (2008), illustrated by Rosemary Wise, with additional enlargements by Sanna Olander.

Fig. 2. Desplatsia Bocq. leaf images. A. D. chrysochlamys (Mildbr. & Burret) Mildbr. & Burret (Harris 4977 (E)). B. D. dewevrei (De Wild. & T.Durand) Burret (Harris 9664 (E)). C–D. D. subericarpa Bocq. (Harris 10194). C. Leaves. D. Leaf base with subulately divided stipules and distinctly inflated petiole in upper part. E–F. Stellate hairs on leaf undersurface. E. D. chrysochlamys (Mildbr. & Burret) Mildbr. & Burret (Harris 5241 (E)). F. D. mildbraedii Burret (Harris 4397 (E)). E–F at the same magnification (40× with microscope). Scale bars = 1 mm. A–D images by D. Harris (RBGE); E–F images by J. Wellsow (RBGE).

Fig. 3. Outline of Desplatsia Bocq. leaf margins. A. D. subericarpa Bocq. (Harris 1387 (E)). B. D. chrysochlamys (Mildbr. & Burret) Mildbr. & Burret (Harris 5402 (E)). C. D. dewevrei (De Wild. & T.Durand) Burret (Harris 7025 (E)). D. D. mildbraedii Burret (Harris 4397 (E)). Shown at 1.5× actual size. Illustrations by Sanna Olander.

Fig. 4. Desplatsia Bocq. fruit images. A–B. D. chrysochlamys (Mildbr. & Burret) Mildbr. & Burret. A. Fresh fruit (Jongkind 8725). B. Cut fresh fruit (Jongkind 9717). C–D. D. dewevrei (De Wild. & T.Durand) Burret. C. Fresh fruit (Harris 9652 (E)). D. Cut fresh fruit (Jongkind 8142). E. D. mildbraedii Burret (Harris 4005 (E)), fresh fruits.F. D. subericarpaBocq. (Harris 10194), fresh fruit.A–B, D images by C. Jongkind; C, E–F images by D. Harris (RBGE).

Fig. 8. Distribution map for Desplatsia mildbraedii Burret.